8-15 is equisolid and 7-14 equidistant projection lenses

AI says that compression at the edges is moderate for 7-14 and significant for 8-15

Would anyone have comparable samples what it would do underwater to see?

I put some examples on page 2 of this thread:

(not sure why the hyperlink box is so wonky.)

7-14 - Nice and sharp, easy to use. Great lens. I can pull some 8-15mm photos for ya if you want. Slightly less sharp (my copy) but not really notable unless corner peaking.

Thank you! Would you be able to find similar pictures 7-14 and 8-15 demonstrating the difference in projection? 7-14 images in that thread look supernice and uniform across the frame and the direct comparison with 8-15 would help even better. Nothing artistic, just pictures like the one with sand in 7-14 thread. Thanks!

A couple of points on this, equidistant and equisolid angle projections are quite close to each other and while lenses are described as such, they probably do not strictly conform to the ideal model. So telling the difference between them from a random photo may be difficult. Ideally you would want a photo of a brick wall or similar taken with the each of the lenses with a tripod in the same position so you can see how the stretching varies. This link for example shows some measurements taken from optical formulas, look at the second and thirs plots where various lenses have been plotted on the curve, they mostly cluster around equisolid but there is quite a variation.

https://www.photonstophotos.net/GeneralTopics/Lenses/Optics_Primer/Optics_Primer_25.htm

Other references state the equisolid has more barrel distortion so more fisheye effect - the forward placement of the subject in the frame.

This link has some projections plotted - it takes some time to look at the plots to see the differences in equisolid and equidistant if you look at orthographic and sterographic plots they are more exaggerated versions of the changes between the first two:

https://paulbourke.net/dome/fisheyetypes/

Kinda hard to find comparable images and both lenses are so good that it is splitting hairs. These are all the 8-15.

The cage gives a pretty good indication of corner sharpness (we do experiments to understand the role of human activities in the ocean and the cages are how we understand the role of fishing).

Also 8-15.

I find the corners are not ALWAYS amazing on the 8-15... but I think I often have the corners out of the DoF and blame the lens rather than focus and user.

When the fisheye/domeport positioning is corrct, there is no reason why the sample images between UW and on the surface should be different. If not, not only optical flaws, but also barell- and pincushion distortion will be pronounces/enhanced, depending on how wrong the positioning is...

Here a link to some samle photos taken with the 7-14mm fisheye lens: https://www.dpreview.com/products/canon/lenses/canon_rf_7-14_2p8-3p5_fisheye_l_stm/sample-photos